Plains hog-nosed snakes are among the rare species that thrive in the sandy, open habitat within Sand Dunes State Forest. They're one of six indicator species the DNR is tracking.

Chris Smith of the Minnesota Department of Natural Resources holds a plains hog-nosed snake surgically implanted with a transmitter. He protects snakes’ locations because people catch them to sell as pets.(Photo: William Camargo, wcamargo@<252>stcloudtimes<129>.com)

ORROCK – Smooth as a strand of pearls, the snake wove between Chris Smith's fingers as he shifted it from hand to hand. Moments earlier, No. 111 was invisible from mere inches away, cooled and camouflaged by a tangle of dried grass.

An antennae and hand-held receiver tuned to the snake's frequency led Smith to this spot within Sand Dunes State Forest. What researchers learn from tracking plains hog-nosed snakes here and in the adjacent Sherburne National Wildlife Refuge could help guide habitat management throughout the state and beyond.

"A lot of the stuff we're learning from this project is new for this species as a whole," said Smith, a Minnesota Department of Natural Resources nongame wildlife biologist.

The project began in 2008 with basic survey work. It continued first with the identification of rare species and now with tracking which habitats they're using. About 100 plains hog-nosed and 100 gophersnakes have been microchipped; 12 plains hog-nosed snakes have been outfitted with transmitters.

At Sand Dunes State Forest, rare species factor into managing for forest vs. savanna
St. Cloud Times

Some might call the landscape scrubby — sun-baked, sandy soil where spiderwort and hoary puccoon blooms punctuated sparse clumps of grass with a bit of lavender and gold. But it makes for good hog-nosed habitat.

"Sherburne County and the Anoka Sand Plain is really the kind of hot spot for this species in Minnesota," Smith said.

He examined a couple of snake holes. A shed skin. No snake. Smith extracted a PIT tag scanner from his backpack, waved it over clumps of grass like a dry cleaner working a steamer. Could be the snake was underground.

Smith turned the snake on its side, revealing an AAA battery-size lump where a transmitter attached to a 6-inch wire was surgically implanted.

Sand Dunes State Forest(Photo: Times graphic)

As of June 25, No. 111 was one of 12 snakes within Sand Dunes State Forest wearing a transmitter. The goal is to outfit 25. That study will continue until the batteries die, probably late next year. Tracking the 200 chipped snakes will continue until the snakes die.

It's way too early for conclusions. But Smith said data collected since April shows the snakes seem to prefer open, sandy areas. Once the DNR starts implementing the management plan it adopted in 2013, that could mean workers would avoid running heavy machinery or starting controlled burns when and where snakes are known to nest.

"Sand Dunes State Forest is a hard place to reach all of our goals," said Hannah Texler, the DNR's St. Paul-based regional plant ecologist. That's because the 11,040-acre forest — 6,000 acres of it managed by the DNR — contains very different habitats.

The drier, sandier habitats including oak savanna tend to remain on the south and west sides of the dunes while the trees of the oak woodlands move in on the cooler, wetter north and east.

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The plant-covered dunes rise up to 60 feet and cover about 2,500 acres in Sand Dune State Forest. These formed between 4,000 and 8,000 years ago. Uncommon in Minnesota, they appear in places where glacier-deposited outwash sands were reformed by winds.(Photo: William Camargo, wcamargo@stclou)

The dunes

Ecologists tend to favor the more open, oak savanna habitats, which would allow plants such as beach heather and critters such as the Blanding's turtle to thrive.

"When I've taken people out there, it doesn't take long to see how really kind of wonderful it is," Texler said. Uncommon in Minnesota, dunes also can be found at Duluth's Minnesota Point (akaPark Point) and Agassiz Dunes SNA in northwestern Minnesota.

These dunes, estimated to be 4,000 to 8,000 years old, today are covered in grass and other plants. In Sand Dunes State Forest, they cover about 2,500 acres, some of them 60 feet tall — the tallest and most developed in the Anoka Sand Plain.

Powdery sand pulls at feet on the path across one dune within Uncas Dunes Scientific and Natural Area just outside Ann Lake Ann Campground. Oaks rim what looks like the lip of a bowl. Strange-looking insects buzz about. The metallic green flashes could be Northern barrens tiger beetles.

"Most of these rare plants and animals like open sand. It's those hot, south- to west-facing dune slopes plus fire that provides the perfect habitat for them," Texler said.

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Starting in the 1940s, pines were planted to help stabilize the former farm fields that became Sand Dunes State Forest. In some places the trees, which are managed for timber harvest, have been thinned out and appear less like rows.(Photo: William Camargo, wcamargo@stclou)

The pines

Fire, part of what keeps an oak savanna's understory open, might not have rolled through Sand Dunes State Forest with such regularity were it not for the Native Americans and early settlers, said Don Mueller, the DNR's Cambridge-based area forestry supervisor.

"Foresters look at it and we look at the amount of nonhuman-caused fire," Mueller said. "It's not all that common in this part of the state."

Partly for that reason, he sees a place for white pines. More than 2,400 acres of trees — many of them red pines — have been planted since the 1940s, when the aim was soil stabilization.

"It is interesting as you're hiking through the woods to understand the shape of (the dunes). It's the more recent natural history that puzzles us," Mueller said.

The agreement

Long-term plans call for restoring oak savanna and oak woodland habitats in some regions of Sand Dunes State Forest, especially in the southern unit.

A February 2013 agreement among DNR divisions would make pine and mixed-oak forest a priority on about 2,860 acres, rare features a priority on about 1,840. Plans consider other habitats, such as meadows, as well as recreation. The campground will remain shaded while some of the surrounding trees may be thinned in an effort to restore habitat favoring rare plants and animals.

"(Forest visitors) will definitely see some change over time from less conifers to more grassland," Mueller said. But much of that change will occur gradually over 10-plus years.

Texler said about 630 acres of forest will be managed for rare features immediately; another 1,400 acres will be managed for rare features eventually.

Meanwhile, snake No. 111 is staying put. She'll likely stick around the immediate vicinity for about a month — until she lays her eggs.

"We don't really know a lot about this species in the wild, which is why we're doing the telemetry," Smith said.

He records what percent of the immediate area is open, what percent is under plant cover. He records surface, underground and air temperatures. He does the same in the surrounding area.

The snakes have been moving more than anticipated at this point in the season — within about a half-mile radius. Smith starts the search at a snake's last recorded location. Sometimes if a hawk or raccoon has carried a snake away, he'll find the transmitter, which often can be reused.

"This time of year they're either on shade from the shrubs or they're underneath that dead vegetation," Smith said. It's 85 degrees in the shade, 110 on the sand.

Smith let this snake go. Within seconds, she disappeared down a hole.

Rare Species

Rare species recorded in Sand Dunes State Forest include eight plants and 10 animals. Among them are state threatened species and state special concern species.